An efficient organic light-emitting diode with silver electrodes

An efficient top-emitting organic light-emitting diode (OLED) was formed of an organic stack sandwiched between a thick Ag anode and a semi-transparent Ag cathode. Interface modification was employed to reduce the injection barriers for both electron and hole from the Ag electrodes into the organic stack. The OLED exhibited superior current-voltage characteristics over a control device having an anode of indium tin oxide. The color could be tuned by varying the thickness of the organic stack. At a thickness of 105 nm, the OLED showed a narrow green emission peak with a device efficiency of about 7.64 cd/A, much greater than 3.36 cd/A obtained from the control device. The color tuning and the efficiency enhancement are attributed to the formation of an optical microcavity in the OLED with Ag electrodes.